Manchester City manager Roberto Mancini has revealed his frustrations at the club's failure to sign the players he wanted last summer.

City had hoped to build on last season's Barclays Premier League title success by bringing in Robin van Persie from Arsenal, but lost out to rivals Manchester United.

The champions were also linked with other big names such as Javi Martinez, Eden Hazard and Daniele di Rossi but instead brought in Jack Rodwell, Matija Nastasic, Maicon, Scott Sinclair and Javi Garcia to mixed success.

With City now trailing United by 12 points at the top of table with 12 games remaining, their hopes of retaining the title are fading and it could be argued what happened last summer cost them.

Mancini told The Guardian: "It's important to realise we have made some mistakes.

"I have made some mistakes and the players have made some mistakes.

"But the first reason is because we didn't do what we should have done in the summer transfer market - we worked really badly in the market."

Mancini's words could be interpreted as criticism of Brian Marwood, the club's former sporting director who has since switched to a role in charge of the Academy.

Mancini expects better recruitment this summer following the arrival of former Barcelona figureheads Ferran Soriano and Txiki Begiristain as chief executive and director of football respectively.

He said: "Ferran came from Barcelona and understands what it needs to be a top club. Txiki played football and knows football.

"They are good men. For this reason, I am optimistic about our future. We now have people who know their football."

Strikers Edinson Cavani and Radamel Falcao of Napoli and Atletico Madrid respectively could be among City's targets this summer and Mancini admires them both.

He said: "Cavani and Falcao would work in England. They have experience. Both players are 26, 27. They are good enough to play in England."

One of City's high-profile signings of the previous season was playmaker Samir Nasri, brought in from Arsenal for £24million.

The Frenchman was among the nominees for player of year during his last campaign at the Emirates Stadium but he has under-performed at City and Mancini has acknowledged his inconsistency.

Mancini said: "I think Samir has fantastic qualities.

"With his quality, he should always play well. Every game he could be the difference.

"A player of this quality could be one of the best players in Europe. But it's not happening.

"Sometimes a player thinks it's enough what they did the year before and doesn't understand that every day they should improve.

"If you are a top player you know you can improve until the last day of your career but sometimes you get players who think it is not important to work and this is their worst mistake.

"Samir can do better than this year. He is a top player but he has not been playing at his level."

Sinclair is also yet to make his mark at the club having made just two league starts but Mancini concedes his had not given him enough opportunities.

He said: "I haven't given him a chance. It's not his fault. He's working well every day and he hasn't caused any problems. I'm very sorry."